Note: for Vulkan to work DRI3 needs to be enabled. 
The file "20-intel.conf" was created by the suggestion of 
the Vulkan git page, found here:
https://github.com/SaschaWillems/Vulkan/wiki/Quick-start-guide

"In order to use Vulkan on Ubuntu you need to enable DRI3, which is disabled by
default. This is not specific to my examples, but a Vulkan driver
requirement."

https://github.com/SaschaWillems/Vulkan/issues/226#issuecomment-242749268

cat << EOF > /etc/X11/xorg.conf.d/20-intel.conf
Section "Device"
   Identifier  "Intel Graphics"
   Driver      "intel"
   Option      "DRI"    "3"
EndSection
EOF

